Japanese Patent Laid-Open Publication No. 7-149289 (JP-A-7-149289) discloses an outboard engine wherein the outer surface of a drive shaft housing (extension case) in the vertical middle of the outboard engine is covered by a cover.
In this outboard engine, the outer surface of the drive shaft housing is covered with a cover made of a synthetic resin to reduce the finishing costs needed to improve the outward appearance of the drive shaft housing, and also to simplify the design of the drive shaft housing.
The cover that covers the outer surface of the drive shaft housing is configured from a two-piece dividable cover having a port cover and a starboard cover.
Thus, in this outboard engine, covering the outer surface of the drive shaft housing with a cover made of a synthetic resin makes it possible to improve the outward appearance of the drive shaft housing and to simplify the external structure of the housing, and also allows for a greater degree of freedom in the design.
However, since this cover is configured from two members, which are the port cover and the starboard cover, a large number of attachment bosses is needed to attach and support these two members on the outer surface of the drive shaft housing, the attachment structure of the cover and the drive shaft housing is complicated, and the number of steps for attachment is increased. Particularly, since the cover is configured from two members, pressure must be applied to both the left and right components when the left and right components are assembled, making operability inferior.
In view of this, the outward appearance of the cover must be simplified, as must the structure for attaching the cover to the drive shaft housing.